666053980164 has 120 divisors (see below), whose sum is σ = 1853808524568. Its totient is φ = 207803335680.

The previous prime is 666053980129. The next prime is 666053980177. The reversal of 666053980164 is 461089350666.

It can be written as a sum of positive squares in 4 ways, for example, as 2125764 + 666051854400 = 1458^2 + 816120^2 .

It is a super-2 number, since 2×666053980164² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 666053980164.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 662902 + ... + 1330994.

Almost surely, 2^666053980164 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666053980164, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (926904262284).

666053980164 is an abundant number, since it is smaller than the sum of its proper divisors (1187754544404).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666053980164 is a wasteful number, since it uses less digits than its factorization.

666053980164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 668307 (or 668296 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 54.

The spelling of 666053980164 in words is "six hundred sixty-six billion, fifty-three million, nine hundred eighty thousand, one hundred sixty-four".